The Court of Cassation (Greek: Άρειος Πάγος, Areopagus, i.e. the "Stone, or Hill, of Ares") is the supreme court of Greece for civil and criminal law. The Court of Cassation's decisions are irrevocable. However, Greece being a member state of the Council of Europe, cases ruled by the Greek Άρειος Πάγος can still be brought to the European Court of Human Rights. If the Court of Cassation concludes that a lower court violated the law or the principles of the procedure, then it can order the rehearing of the case by the lower court. It examines only legal and not factual issues and it is the highest degree of judicial resort. The current president of the Court is Georgios Kalamidas. The court consists of the president and the attorney-general, ten vice-presidents, fifty five areopagites and fourteen deputy attorneys-general. The members of the Supreme Court enjoy functional and personal independence, as do all members of the judiciary, and are members for life, but they are required by law to retire at the age of 67 (article 87 paragraph 1 and article 88 paragraphs 1 and 5 of the Constitution of Greece).

The Areios Pagos is named after the first court of androfonies (crimes of murder), founded somewhere between 1500-1300 BC by Theseus and King Cecrops, which was situated on the rocky hill named after the god Ares in Athens. This highest court of antiquity was named the Areios Pagos Parliament and consisted of members for life, the Areopagites, who held all powers. In 462 BC a great part of the administrative and judicial powers was conveyed to the Heliaia, the 'Parliament' and the Ekklesia (public assembly). The institution was copied in many Greek city-states, and survived until well into the late Roman period, when the cities' internal autonomy was curtailed.

On 16 October 1834, the Areios Pagos was founded as the supreme court of modern independent Greece by royal decree. Instead of giving the name Court of Cassation, it was finally decided for the supreme court to be named in honour of its ancient equivalent. The first supreme court justices were nominated on 13 January 1835 by royal decree. The first president of the supreme court was Christodoulos Klonaris (1788-1849), attorney at law in the city of Nafplion and the minister of justice in the government of Ioannis Kapodistrias. The first attorney-general was Andronikos Paekos, who up until then was the presiding judge of the temporary court of Missolonghi.